Purpose – This thesis investigates the parameter Cubic Wing Loading (CWL). It is the mass of the aircraft divided by the wing surface area taken to the power of 3/2. As such the unit of the denominator is converted from m² to m³ and CWL has the unit of kg/m³. Classical Wing Loading (WL) is aircraft mass divided by wing area. It is investigated, if CWL (unlike WL) is independent of aircraft size, if it has advantages in preliminary aircraft design, and if it can be used as a basis for interesting correlations. 

Methodology – Aircraft preliminary sizing equations for passenger jet aircraft are rewritten to replace WL with CWL. Aircraft statistical data are investigated with respect to CWL. 

Findings – It is known that WL increases with aircraft size. Unfortunately, also CWL depends on aircraft size. However, CWL decreases with aircraft size. CWL introduced to preliminary sizing leads to additional (but manageable) iterations compared to preliminary sizing based on WL. Correlations with other aircraft design parameters are weak and no relation with accident rates for high CWL aircraft is found. 

Research Limitations – 209 airplanes are studied for initial statistical correlations. Some correlations were limited to 72 airplanes due to lack of detailed data. 

Practical Implications – There are no advantages to replace WL by CWL in passenger aircraft preliminary sizing. 

Originality – This seems to be the first report to fully investigate CWL with respect to passenger aircraft and to offer a related user-friendly preliminary sizing spreadsheet.